Homoconjugation-Enabled Kagome Bands in a Layer-Decoupled Two-Dimensional Conductive Triptycene-Based Metal-Organic...

Two-dimensional (2D) conductive metal-organic frameworks (MOFs) have been widely investigated as porous conductors in which in-plane electronic delocalization arises from π-d conjugation, while additional out-of-plane charge transport emerges through interlayer π-π interactions. However, in most 2D MOFs, interlayer interactions lead to stacking-dependent electronic and transport properties, introducing substantial structural and electronic variability that obscures the intrinsic physical behavior. Here, we demonstrate that incorporating a triptycene-based core into Ni-hexaiminophenylene linkages yields crystalline 2D frameworks, Ni₃(HITrip)₂, in which interlayer π-π coupling is effectively eliminated. As a result, the material preserves its intrinsic in-plane electronic topology in the bulk, independent of the stacking arrangement. The material exhibits a high bulk electrical conductivity of 0.58 S cm^-1 despite having a finite band gap, a large surface area, and a strongly anisotropic transport. Density functional theory calculations suggest that these properties arise from the preserved symmetry-protected Dirac cone trivial topology within the layer-stacked bulk structure, governed by radicals in the quartet-state linker. This study establishes a general design strategy in which linker geometry is leveraged to suppress interlayer coupling, enabling experimental realization of monolayer-like electronic structures in stacked 2D MOF and providing a robust experimental platform for low-dimensional 2D MOF electronics and kagome lattice-based topological studies.